The answer is Amazon EFS with mount targets in multiple Availability Zones. This is correct because Amazon EFS provides a fully managed, NFS-based shared file storage solution that can be mounted concurrently by multiple Linux EC2 instances across different AZs, and by deploying mount targets in each AZ, the file system remains accessible even during an AZ failure since traffic automatically reroutes to surviving targets. On the SAA-C03 exam, this scenario tests your understanding of resilient, shared storage for Linux workloads—a common trap is choosing Amazon EBS Multi-Attach, which only works within a single AZ and is limited to Nitro-based instances, or using S3, which is object storage not a POSIX-compliant file system. Remember the key distinction: EFS is the only AWS-native managed file system that supports concurrent access across AZs for Linux instances. Memory tip: “EFS for Elastic File Sharing across AZs.”
SAA-C03 Design Resilient Architectures Practice Question
This SAA-C03 practice question tests your understanding of design resilient architectures. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. A key principle to apply: amazon EFS is a fully managed NFS (NFSv4.0 and NFSv4.1) file system.. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A warehouse integration service must use shared file storage across Linux EC2 instances in multiple Availability Zones. The storage must remain available during an AZ failure. Which service should be used? The architecture review board prefers a managed AWS-native control.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Amazon EFS with mount targets in multiple Availability Zones
Amazon EFS provides a fully managed, NFS-based shared file system that can be mounted concurrently by multiple Linux EC2 instances across different Availability Zones. By creating mount targets in each AZ, the file system remains accessible even if one AZ fails, as traffic is automatically routed to the surviving mount targets. This meets the requirement for shared, resilient storage with a managed AWS-native control plane.
Key principle: Amazon EFS is a fully managed NFS (NFSv4.0 and NFSv4.1) file system.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
Amazon EFS with mount targets in multiple Availability Zones
Why this is correct
EFS is regional file storage and supports mount targets across AZs.
Related concept
Amazon EFS is a fully managed NFS (NFSv4.0 and NFSv4.1) file system.
✗
S3 mounted as a POSIX file system without a file gateway
Why it's wrong here
S3 is object storage and does not provide native POSIX shared file semantics.
✗
Instance store volumes
Why it's wrong here
Instance store is ephemeral and tied to a single instance.
✗
An EBS volume attached to all instances
Why it's wrong here
A standard EBS volume is zonal and cannot be attached broadly as shared file storage.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse EBS Multi-Attach (which is limited to a single AZ and specific instance types) with the cross-AZ shared file system capability of EFS, or incorrectly assume S3 with a FUSE mount can replace a POSIX-compliant file system.
Detailed technical explanation
How to think about this question
EFS uses the NFSv4.1 protocol and leverages AWS Global File System to replicate data across multiple AZs within a region, providing strong read-after-write consistency. Under the hood, each mount target is an IP address in a VPC subnet that routes NFS traffic to the EFS file system’s distributed storage backend; during an AZ failure, DNS-based or client-side failover can redirect to a mount target in a healthy AZ. A real-world scenario is a containerized application using EFS for persistent shared storage across ECS tasks in different AZs, where the file system remains available even if one AZ’s mount target goes down.
KKey Concepts to Remember
Amazon EFS is a fully managed NFS (NFSv4.0 and NFSv4.1) file system.
EFS is a regional service, supporting mount targets across multiple Availability Zones.
Data stored in EFS is highly durable and available, designed to withstand an AZ failure.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Amazon EFS is a fully managed NFS (NFSv4.0 and NFSv4.1) file system.
Real-world example
How this comes up in practice
A media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
What to study next
Got this wrong? Here's your next step.
Review amazon EFS is a fully managed NFS (NFSv4.0 and NFSv4.1) file system., then practise related SAA-C03 questions on the same topic to reinforce the concept.
Design Resilient Architectures — This question tests Design Resilient Architectures — Amazon EFS is a fully managed NFS (NFSv4.0 and NFSv4.1) file system..
What is the correct answer to this question?
The correct answer is: Amazon EFS with mount targets in multiple Availability Zones — Amazon EFS provides a fully managed, NFS-based shared file system that can be mounted concurrently by multiple Linux EC2 instances across different Availability Zones. By creating mount targets in each AZ, the file system remains accessible even if one AZ fails, as traffic is automatically routed to the surviving mount targets. This meets the requirement for shared, resilient storage with a managed AWS-native control plane.
What should I do if I get this SAA-C03 question wrong?
Review amazon EFS is a fully managed NFS (NFSv4.0 and NFSv4.1) file system., then practise related SAA-C03 questions on the same topic to reinforce the concept.
What is the key concept behind this question?
Amazon EFS is a fully managed NFS (NFSv4.0 and NFSv4.1) file system.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A warehouse integration service must use shared file storage across Linux EC2 instances in multiple Availability Zones. The storage must remain available during an AZ failure. Which service should be used? The team wants the control to be enforceable during normal operations.
hard
✓ A.Amazon EFS with mount targets in multiple Availability Zones
B.S3 mounted as a POSIX file system without a file gateway
C.Instance store volumes
D.An EBS volume attached to all instances
Why A: Amazon EFS provides a fully managed, POSIX-compliant NFS file system that can be mounted concurrently on multiple Linux EC2 instances across different Availability Zones. By creating mount targets in each AZ, the file system remains accessible even if one AZ fails, because the other mount targets continue to serve traffic. EFS also supports lifecycle policies and IAM enforcement to control access during normal operations, meeting the requirement for enforceable control.
Variation 2. A warehouse integration service must use shared file storage across Linux EC2 instances in multiple Availability Zones. The storage must remain available during an AZ failure. Which service should be used? The design must avoid adding custom operational scripts.
hard
✓ A.Amazon EFS with mount targets in multiple Availability Zones
B.S3 mounted as a POSIX file system without a file gateway
C.Instance store volumes
D.An EBS volume attached to all instances
Why A: Amazon EFS provides a fully managed, POSIX-compliant NFSv4.1 shared file system that can be mounted concurrently across multiple Linux EC2 instances. By deploying mount targets in multiple Availability Zones, the file system remains accessible even if one AZ fails, satisfying the high-availability requirement without any custom scripts.
Variation 3. A warehouse integration service must use shared file storage across Linux EC2 instances in multiple Availability Zones. The storage must remain available during an AZ failure. Which service should be used?
hard
✓ A.Amazon EFS with mount targets in multiple Availability Zones
B.S3 mounted as a POSIX file system without a file gateway
C.Instance store volumes
D.An EBS volume attached to all instances
Why A: Amazon EFS provides a fully managed, scalable, and elastic NFS file system that can be mounted concurrently on multiple Linux EC2 instances across different Availability Zones. By configuring mount targets in each AZ, the file system remains accessible even if one AZ fails, because the other mount targets continue to serve traffic. This meets the requirement for shared, highly available file storage across AZs.
Variation 4. A patient portal must use shared file storage across Linux EC2 instances in multiple Availability Zones. The storage must remain available during an AZ failure. Which service should be used? The design must avoid adding custom operational scripts.
hard
A.Instance store volumes
✓ B.Amazon EFS with mount targets in multiple Availability Zones
C.An EBS volume attached to all instances
D.S3 mounted as a POSIX file system without a file gateway
Why B: Amazon EFS provides a fully managed, scalable, and shared file system that can be mounted concurrently on multiple Linux EC2 instances across different Availability Zones. By creating mount targets in each AZ, the file system remains accessible even if one AZ fails, meeting the high availability requirement without custom scripts.
Variation 5. A patient portal must use shared file storage across Linux EC2 instances in multiple Availability Zones. The storage must remain available during an AZ failure. Which service should be used? The architecture review board prefers a managed AWS-native control.
hard
A.Instance store volumes
✓ B.Amazon EFS with mount targets in multiple Availability Zones
C.An EBS volume attached to all instances
D.S3 mounted as a POSIX file system without a file gateway
Why B: Amazon EFS provides a fully managed, shared POSIX-compliant file system that can be mounted concurrently across multiple Linux EC2 instances. By creating mount targets in multiple Availability Zones, the file system remains accessible even if one AZ fails, meeting the high-availability requirement. This aligns with the architecture review board's preference for a managed AWS-native control.
Variation 6. A patient portal must use shared file storage across Linux EC2 instances in multiple Availability Zones. The storage must remain available during an AZ failure. Which service should be used?
hard
A.Instance store volumes
✓ B.Amazon EFS with mount targets in multiple Availability Zones
C.An EBS volume attached to all instances
D.S3 mounted as a POSIX file system without a file gateway
Why B: Amazon EFS provides a scalable, fully managed NFS file system that can be mounted concurrently on multiple Linux EC2 instances. By creating mount targets in multiple Availability Zones, the file system remains accessible even if one AZ fails, ensuring high availability and shared file storage across instances.
Last reviewed: Jun 11, 2026
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